The figure shows how to couple two TTL circuits using an optical coupler to obtain isolation. The circuit is shown in the August 1992 issue of Radio Electronics magazine.
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
This circuit was obtained in an old Elektor. It is a reference, since the integrated products of the...
This circuit was found in a European technical documentation from 1991. It is a circuit that must...